The invention relates to a device for sealing a coupling unit for an optoelectronic component against contaminants, the coupling unit forming at least one opening, in particular, for receiving an optical plug or plug part, characterized by a sealing element with at least one open end, which can be introduced into the opening of the coupling unit and thereby seals the opening, and with at least one cavity, which is formed in the sealing element and adjoins the end of the sealing element. The device is suitable in particular for sealing an optoelectronic transceiver.
It is known to connect optoelectronic transceivers by means of optical plug-in connectors, for instance to an optical network. Coupling of light into and out of the transceiver takes place by means of coupling units, which have in each case an opening for receiving an optical plug or plug part. Two coupling units with associated openings are generally provided for this purpose, to be specific a first coupling unit by means of which coupled-in light is directed to a photodiode module and a second coupling unit by means of which light produced by a laser-diode module is coupled out. The two coupling units may also be formed as one part.
It is necessary that openings formed on coupling units of this type for receiving optical plugs are sealed securely against contaminants. This problem arises in particular during the assembly, transportation and fitting of optoelectronic transceivers, before the optical plugs to be coupled on are inserted into the respective openings. Problems arise in particular when there is a change in temperature, which is naturally accompanied by an expansion or compression of air inside the coupling unit. Such changes in temperature occur for example during the testing of a transceiver unit or during the fitting of a transceiver by means of soldering. During the cooling down of the heated transceiver or heated coupling unit, there is then the risk of contaminants and also moisture being sucked into the coupling unit and contaminating the optical channel on account of the air being compressed. In addition, there is the risk of flushing fluid, used for flushing away remains of solder, getting into the coupling unit after the soldering operation has been completed.
Consequently, it is to be endeavored to seal the openings of a coupling unit in such a way that they are hermetically sealed from the outside atmosphere.
For this purpose, it is known to use specially made process plugs, which have two unconnected and separately formed sealing regions, which are inserted into the respective openings of the coupling unit. This solution is relatively complex and cost-intensive.
This object is achieved according to the invention by a device for sealing a coupling unit for an optoelectronic component, in particular an optoelectronic transceiver, against contaminants, the coupling unit forming at least one opening, in particular, for receiving an optical plug or plug part, characterized by a sealing element with at least one open end, which can be introduced into the opening of the coupling unit and thereby seals the opening, and with at least one cavity, which is formed in the sealing element and adjoins the end of the sealing element. Preferred and advantageous configurations of the invention are specified in the subclaims.
The present invention is based on the object of providing a device for sealing a coupling unit for an optoelectronic component against contaminants which ensures secure sealing of the coupling unit and at the same time can be produced in a low-cost and simple way.
This object is achieved according to the invention by a device having the features of claim 1. Preferred and advantageous configurations of the invention are specified in the subclaims.
The invention accordingly envisages the provision of a sealing element with at least one open end, which can be introduced into the opening of the coupling unit and thereby seals the opening. Additionally formed in the sealing element is at least one cavity, which adjoins the end of the sealing element.
The solution according to the invention provides in the sealing element a volume of air which directly adjoins the opening of the coupling unit to be sealed, so that the interior of the coupling unit and the volume of air of the sealing element form a closed air system. As a result, positive or negative pressures in the coupling unit can be equalized by the adjoining volume in the sealing element. In particular, there is no possibility of outside air, and consequently contaminants or moisture, being sucked into the coupling element when air contracts in the coupling unit on account of cooling down taking place. Consequently, the equalizing of the negative pressure occurring takes place by means of the volume of air of the sealing element separated from the atmosphere.
The sealing element preferably has a first open end and a second open end, which can be introduced into a first opening and a second opening of the coupling unit and thereby respectively seal the openings, a cavity adjoining each end of the sealing element. This configuration is suitable for sealing coupling elements for transceivers which have a first opening for the coupling in of light and a second opening for the coupling out of light.
In an advantageous development of this configuration, a continuous cavity which connects the two ends of the sealing element to each other is formed in the sealing element. This variant manages with only one cavity in the sealing element, which extends between the two open ends and can accordingly be produced in a simple and low-cost way.
In a preferred configuration of the invention, the first and second ends of the sealing element are arranged adjacently and are connected to each other by a cavity bent in a U-shaped manner. The first and second ends of the sealing element are in this case preferably designed in each case in a hose-like form, the hose-like ends bearing against sealing surfaces of the first and second openings of the coupling element and thereby sealing the openings in an airtight manner with respect to the outside atmosphere. However, in this case sealing with respect to the cavity of the sealing element does not take place, so that the sealing can be designed in a much simpler form in comparison with the prior art.
In a preferred configuration of the invention, the sealing element is a flexible hose, the two ends of which can be inserted into the first and second openings of the coupling element. The hose in this case preferably consists of a flexible silicone rubber. Use of a flexible hose material has the effect of additionally equalizing the occurrence of positive and negative pressures in the coupling element.
The ends of the flexible hose are slipped over tubular or flange-shaped connection elements provided in the respective openings of the coupling element. As a result, sealing of the coupling element is brought about in a simple and low-cost way.
The flexible hose is preferably bent in a U-shaped manner, the two ends of the hose being arranged next to each other in the first and second openings of the coupling element. In a development of this configuration, a holding clip is additionally provided, fastened in the U-shaped region to the hose and fixing the latter in the U-shaped alignment. The holding clip additionally facilitates the handling of the hose bent in a U-shaped manner and its insertion into the coupling element.
In an alternative configuration, the sealing element has at least two-cavity chambers, one cavity chamber respectively adjoining one end of the sealing element. The cavity chambers are in this case preferably closed by a membrane on their side respectively remote from the open end. Equalizing of positive or negative pressures is improved as a result.
The invention is explained in more detail below on the basis of several exemplary embodiments with reference to the figures of the drawings.